Ejecting apparatus for exhausting air or other fluids



Feb. 27, 1923. 1,447,014

R. N. EHRHART EJECTING APPARATUS FOR EXHAUSTING AIR OR OTHER FLUIDS Filed May 10, 1919 Weight JIM-d Exhausted WITNESS INVENTOR.

Patented Feb. 27, 1923.

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RAYMOND N. EHRHART, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO ELLIO'IT COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

nanc'rme APPARATUS roa nxnxusrme AIR OR OTHER FLUIDS.

' Application filed May 10, 1919. Serial No. 296,236.

To all whom it may concern:

Be it known that I RAYMOND N. EHRHART, a citizen of the United States, residing at Pittsburgh, Allegheny County, Pennsylvania, have invented a new and useful Improvement in Ejecting Apparatus for Exhausting Air or Other Fluids, of which the following is a full, clear, and exact description, reference being'had to the accompanyingv drawing, forming part of this specification, in which Figure 1 is a diagrammatic section of apparatus embodying my invention, and

Figure 2 is a diagram illustrating the relative efliciency of my invention. 7

My invention has relation'to ejecting apparatus for exhausting air or other fluids from condensers and the like; and is designed to provide for the more efiicient operation of such apparatus. The invention relates more particularly to that class of ejectors wherein the steam or other fluid is condensed between the various ejector stages. In this class of ejectors, a condenser is employed between the first and second stages of the ejector for the purpose of condensing out the vapor, so that the second stage of the ejector has to handle the air only. Such arrangements are particularly adaptable to very large plants where ahigh degree of efliciency is required, but are not as applicable to many modern plants where simplicity and direct results are of more importance than the highest degree of efliciency.

Referring to the accompanying drawing in which I have illustrated an embodiment of my invention in a diagrammatic manner, the

numeral 2 designates the exhaust connection leading to the condenser or other vessel to be exhausted, 3 indicates the first stage ejector comprising a nozzle or nozzles 4 d1scharging into the usual converging-diverging difl'user structure; 5 is the intermediate condenser, 6' the first ejector of the second stage which exhausts the air or other fluid from the condenser 5, and 7 a second ejector in series with the ejector 6. Each of the ejectors 6 and 7 is provided with a nozzle or nozzles 8 and'with a converging-diverging difiusing structure such as shown for the condenser 3. It will thus be seen that I provide two ejectors arranged in series in a separate stage. Although these two ejectors are shown as arran ed in a straight line, they may of course he at an angle to each other. The condenser 5 is provided with any suitable means such as indicated at 9 whereby the condensate may be discharged therefrom.

In Figure 2 I have shown a diagram which illustrates the action of my improved apparatus as compared with apparatus wherein a single ejector is used for exhausting air from the condenser 5. In this diagram the ordinates represent absolute pressures of mercury while the abscissae represent weights of fluid exhausted from the condenser 5. The curve a, a illustrates the action of an apparatus having a single ejector in the second stage;'-while the curve I), 72 illustrates the operation of my improved apparatus. This diagram is based upon substantially the same steam consumption for both forms of apparatus. It will be evident from this diagram that if the system is so designed that the second ejector 7 operates within the limits of thepoints 0 and 3 it is considerably more eflicientthan the old apparatus, an that superior economy in steam result. For example, if the suction pressure of the second ejector is 2% inches of mercury, it can exhaust from the intermediate condenser an amount of air represented by the line m where my improved apparatus is used; whereas the single-stage ejector could only exhaust the amount represented by the line n. In other words, for the same steam consumption a two-stage ejector will be more efiicient in removing the same amount of fluid from the intermediate condenser, and a lesser amount of steam is required. For

handling a small amount of air at high vacua or states of rarefication, the twostage ejector beyond the condenser will require much less steam than will a singlestage ejector. However, if the amount of fluid flowing to the ejector from the discharge of the condenser 5 is very large (that is, beyond the point y) then a single-stage ejector attached to the discharge of the condenser 5 will be more eificient. For condenser service, however, small amounts of least less steam by the use of my invention than with the arrangements previously used.

These determinations also indicate that if the pressure is materially more than 3 of mercury, my invention, is equal to or somewhat less eflicient than the old arrange- --ments; but as the pressures required for condensers which serve steam turbines are generally less than 3", my invention provides an apparatus of materially greater efliciency than any previous apparatus with which I am familiar.

I claim: 1. Ejecting apparatus for exhausting air or other fluids, comprising a single-stage steam ejector, a condenser into which the ejector discharges, and a multi-stage e ector for exhausting the condenser, the different stages of the multi-stage ejector being di rectly connected to each other, substantially as described.

2. Ejecting apparatus for exhausting air or other fluids, comprising a single-stage steam ejector designed to be connected to the vessel to be exhausted, a condenser; into which the said ejector discharges, and a lyre-73cm multi-stage ejector connected to the gas offtake of the condenser, the different stages of the multi-stage ejector being directly connected to each other, substantially as described. t

3. Ejecting apparatus for exhausting air or other fluids, comprising a single-stage ejector, a condenser into which the ejector discharges, and a two-stage ejector connected to the offtake of the condenser, said twostage ejector being constructed and arranged to compress over a greater range than the single-stage ejector, substantially as described.

4. Ejecting apparatus for exhausting air or other fluids, comprising a single-stage ejector, a condenser into which the ejector discharges, and a two-stage ejector connected to the ofi'take of the condenser, said twostage ejector being constructed and arranged to compress over a greater range than the single-Sta e ejector, together with means for Withdrawing the condensate from said condenser, substantially as described.

In testimony whereof, I have hereunto set 111 hand.

y RAYMOND N. EHRHART. 

